Is it permissible to favor one daughter over another in inheritance or a gift because she is in greater financial need, and is it permissible to favor one heir over another for the same reason?

The division of a living person's property among his children is considered a gift, not an inheritance. Inheritance is divided according to the Sharia-prescribed division among the heirs, regardless of their circumstances. Inheritance enters the ownership of the heir by compulsion. An adult of sound judgment may waive his share to whomever he wishes, but it is not permissible to divide an inheritance in a way other than the Sharia-prescribed division by compulsion upon the heirs. A father must be just in his gift among his children, unless there is a valid reason.